This invention relates generally to systems for providing site-specific information to an operator of a vehicle, and more particularly, to a data communication system which employs electromagnetic data communication between a data storage device installed along a roadway and a vehicle moving therealong.
In addition to being an immediate problem, highway congestion in the United States is expected to continue to increase over the next several decades to the point where the delays experienced under the present conditions as a result of congestion, will quadruple before the end of the first decade of the twenty-first century. Moreover, it is becoming evident that the traditional approaches to the problem of highway congestion, which have included highway expansion programs, will not keep up with the pace of highway usage.
Approximately two-thirds of the vehicle-hours of delay in traffic congestion is the result of accidents and other incidents which are precipitated primarily by the poor judgment and actions of drivers. There clearly exists a need for a system which assists drivers in making highway travel a more orderly process. This is especially crucial in view of the nonlinear relationship between traffic and congestion, wherein an increase of 50% in traffic will produce approximately 400% increase in congestion, beyond the levels that are encountered at the present time.
There are a number of factors which cooperate to produce the need for an increase in the efficiency with which traffic is directed. it is now well recognized that, although highway construction generally kept pace with increases in travel demands during the last few decades, the expansion in the capacity of the highways has stimulated new development and increased the vehicular traffic. At the present, however, programs for expanding interstate highway systems have been winding down, while travel demand has accelerated. In fact, it has been suggested that the worsening crisis in vehicular traffic has now reached the point where mere expansion in the highway capacity will not eliminate the congestion crisis. Moreover, time, money, and real estate are all too scarce to permit highway expansion to be offered in and of itself as the solution to the congestion problem.
One area of very high inefficiency in the traffic system is the human operator. The proper function of the highway system is almost entirely based upon the perceptual, cognitive, and vehicle control skills of human operators. The human factors associated with the individual drivers determine the manner in which each vehicle participates in the traffic stream. Moreover, since individuals cover a tremendous range of attentiveness, attitude, alcohol/drug impairment, and manipulative capabilities, highway systems therefore must be designed to require during use significantly less than the full potential skills of the average driver. It is these factors which determine the headway between vehicles, the choice of lanes of travel, the placement of the vehicle within the lane, the timing of merge maneuvers, the regularity of flow along a dense stream of vehicles, and the selection of a route to be followed to the final destination.
In the course of operating a vehicle, each driver interprets the environment and pursues immediate and longer-term driving strategies. However, drivers can see only a hundred feet ahead and therefore cannot make the most efficient choices of route, lane selection, or speed. Moreover, when incidents occur along the highway, drivers react irrationally, slowing to exaggerated creep speeds while delaying thousands of others so as to observe unnecessarily the scene of the disruption. Human decision making and control skills have the strongest influence on the frequency of collisions, the nominal traffic speed along an artery, and the extent to which an overall road network is utilized to meet the traffic demand.
The foregoing makes evident that the primary drawback in the present vehicle-highway system is a general lack of vehicle-highway control intelligence in view of the highly limited amount of information which is available to each driver. Although certain types of vehicle control intelligence have been applied to improve the efficiency of highway transportation, such as electronic engine control systems and anti-lock braking systems, the drivers are the only source of intelligence which is applied to regulate and control the characteristics and parameters of highway traffic.
It is, therefore, an object of this invention to provide a simple and economical system for providing site-specific information to a driver of a vehicle.
It is also an object of this invention to provide a simple and economical system for providing to a driver information on highway conditions beyond the field of unaided view.
It is another object of this invention to provide a system which increases highway throughput without requiring conventional expansion thereof.
It is a further object of this invention to provide an intelligence system which reduces the need for frequent oscillations in vehicle speed between high-speed spurts and nearly-stopped motion.
It is also a further object of this invention to provide a system which provides drivers with current information on the condition of congestion ahead.
It is additionally an object of this invention to provide a system which provides a driver with guidance for pursuing alternate routes.
It is yet a further object of this invention to provide a system which permits centralized monitoring of traffic conditions on a plurality of highways simultaneously.
It is also another object of this invention to provide an effective system for avoiding collisions between vehicles.
It is yet an additional object of this invention to provide a system which permits a driver to make changes in the contemplated route of travel in response to information on highway and/or traffic conditions ahead of the driver's field of view.
It is still another object of this invention to provide a system which provides to a lost driver information pertaining to the vehicle's location and heading.